The invention relates to an arrangement for controlling the supply of inlet air to a vehicle. The arrangement incorporates a control unit arranged to indicate and initiate supply of intake air to at least three intake air regions in the vehicle, and a control arrangement which is designed depending on the setting of the control unit, to control dampers situated in ducts which lead to said intake air regions. This control arrangement incorporates a cam arrangement which is designed to control an arm, arranged for each intake air region, for variable setting of at least one of said dampers between an open and a closed position.
Ventilation arrangements in vehicles which supply intake air to three intake air regions, which in a vehicle are usually a defroster region, a panel region and a floor region, are commonly subject to the limitation that the intake air cannot be distributed simultaneously, and in desired quantities, to said intake air regions.
A known ventilation arrangement according to GB 2 212 587 B incorporates a rotatable control unit arranged to initiate and supply intake air to three intake air regions. That control unit can only distribute intake air to at most two regions simultaneously. The rotary motion of the control unit is transmitted via a cable to a control arrangement which incorporates a cam arrangement for controlling arms which incorporate dampers for said intake air regions. This cam arrangement incorporates a cam device with three recesses for controlling the respective arms. This form of cam arrangement does not make it possible to eliminate the aforesaid limitation.
Another known ventilation arrangement supplying intake air to said three intake air regions in a vehicle uses three separate control devices, one for each intake air region. Each of these three control devices is moved individually along its separate path and separately controls its control arrangement in order to distribute intake air to the respective region. This control unit makes it possible for intake air to be supplied entirely variably to said intake air regions. It has disadvantages in that it occupies a large amount of space on the instrument panel and involves three separate control arrangements.
In heavy-duty vehicles it is often desirable to keep down the number of electronically controlled components, so the present invention relates to a mechanical arrangement for controlling the intake air supply in the vehicle.